1. Technical Field
The disclosure relates to a method and a device of manufacturing a speaker according to a sheet to roll manufacturing process.
2. Background
Vision and hearing are two humanity's most direct sensory responses. Therefore, scientists have been dedicated to develop various renewable visual and auditory related systems. Regarding the speakers, moving coil speakers dominate the entire market. In recent years, with people's increasing demands for sensing quality, and development trends of 3C products (computer, communication, consumer electronics) for lightness, slimness, shortness and smallness, a power-saving, light and slim speaker designed according to an ergonomic requirement is developed. Such speaker can be used in either large-size flat speakers or small walkman headphones and stereo mobile phones, and in a foreseeable future, such technology may have a plenty of demands and application development.
Presently, electroacoustic speakers are mainly grouped into direct and indirect radiation speakers, and according to driving methods thereof, the speakers are approximately grouped into moving coil, piezoelectric and electrostatic speakers. The moving-coil speaker is widely used, and a technique thereof is relatively mature. However, due to its innate structural defect, a shape of the moving coil speaker cannot be flatized, so that it is not suitable for applying to 3C products and home theatres having development trends of smallness and flatness.
In the piezoelectric speaker, according to a piezoelectric effect of a piezoelectric material, an electric field is applied to the piezoelectric material to cause deformation, so as to drive a vibrating membrane to generate sound. Although such speaker has a flat and miniaturized structure, its sound quality is limited.
Main products of the electrostatic speaker in the market include hi-end earphones and loudspeakers. A functional principle of the conventional electrostatic speaker is to use two fixed porous electrode plates to clamp a conductive vibrating membrane to form a capacitor, and by supplying a direct current (DC) bias to the vibrating membrane and supplying an alternating current (AC) voltage to the two fixed electrodes, the conductive vibrating membrane is vibrated due to an electrostatic force generated under a positive and a negative electric fields, so as to radiate a sound. The bias of the conventional electrostatic speaker has to reach hundreds to thousands voltages, so that an external amplifier with a high price and a great size has to be applied, and therefore application thereof cannot be widespread.
Presently, manufacturing of the speaker still applies a design and producing method of a single unit, for example, a speaker disclosed by a U.S. Pat. No. 3,894,199.
Regarding the electrostatic speaker, the U.S. Pat. No. 3,894,199 discloses an electroacoustic transducer structure. Referring to FIG. 1, FIG. 1 is a schematic diagram illustrating a conventional speaker unit. The speaker unit includes two fixed electrodes 110 and 120 disposed at two sides. The fixed electrodes 110 and 120 have a plurality of holes for dispersing the generated sound. A vibrating membrane 130 is disposed between the fixed electrodes 110 and 120. The fixing structure 140 is made of an insulation material, and is used for fixing the fixed electrodes 110 and 120 and the vibrating membrane 130. The fixed electrodes 110 and 120 are respectively coupled to an AC voltage source 160 through a transformer 150. When an AC signal is transmitted to the fixed electrodes 110 and 120, potentials of the AC signal are alternately changed, so that the vibrating membrane 130 is vibrated due to a potential difference of both sides, so as to generate a corresponding sound. However, according to the above configurations, a sound pressure output is required to be enhanced, so that an additional power device is used for driving. Therefore, not only the device size is huge, but also relatively more devices are used, and a cost thereof is relatively high. Moreover, since the fixing structure 140 has to fix the fixed electrodes 110 and 120 and the vibrating membrane 130, flexibility of the electroacoustic transducer structure cannot be achieved.
In addition, according to the conventional techniques, during a mass production, individual units have to be produced one-by-one, and the speaker generally has a fixed size or shape, so that effective mass production and cost reduction cannot be achieved, and features of softness, thinness, low driving voltage and flexibility of the speaker cannot be achieved.